Telephone system.



PATENTED OCT. 13, 1903.

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PATENTED 00T. 1s, 1903. o. B. SMITHlv TELEPHONE SYSTEM.

APPLICATION FILED DE(}.18. 1899. RENBWED 00T. 22, 1902.

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v n ha, if", .i .h lllllllln" l i i 'l No. 741,284. PATENTED OCT. 13, 1903. C. B. SMITHn TBLBPHONESYSTEM APPLIGATION FILED DBO. 1s. 18991M RELNEWED 00T. 22. 19o2.

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Unirse STATES Patented october is, 190e.

Parent enten.

TELEPHONE SYSTEM.

"PEIFICATION forming part of Letters Patent NO. 741,284, dated October 13, 1903i. Application led December 18, 1899. Renewed October 22,1902. Serial No. 128,249. (No model.)

To all whom zr may concern:

Be it known that I, CHARLES B. SMITH, a citizen of the United States, residing in New York city, borough of Manhattan, State of New York,have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification.

My invention relates more particularly to improvements in thevclass of telephone sys- IO tems having a central office from which eX- tend a plurality of lines on which a plurality of subscribers stations are located, although my invention may be used in conjunction with lines having individual subscribers thereon.

The object of my invention is to provide a plurality of telephoning-lines arranged in pairs with electrically-operating devices at several subscribers stations on such lines arranged to select any idle pair of such lines and to connect such pair through the telephone instruments in the stations. At the central office I provide means to break the normal circuit of any pair of lines to prevent interference by two subscribers, and at central also are located devices to enable any pair of lines to be connected with any other pair.

The invention also consists in the novel details of improvement that will be morefully o hereinafter set forth and then pointed out in.

the claims.

Reference is to be had to the accompanying drawings, forming part hereof, wherein- Figure 1 is a diagrammatic view of a telephone systern embodying my invention. Fig. 2 is a face View of the devices I have provided for the subscribers stations to produce a call at central and to connect a corresponding telephone with a pair of idle conductors. Fig. 3 is an edge View thereof looking from the right in Fig. 2. Fig. 4 is a face view looking at the opposite side to that shown in Fig. 2, and Fig. 5 is an inverted plan View of Fig. 4 looking in the direction of the arrows.

In the accompanying drawings, in which similar letters and numerals of reference indicate corresponding parts in the several views, A indicates generally a central office at which are located appropriate devices for 5o use in connection with my improvements.

B C D indicate subscribers stations which are located on lines or conductors leading from central. In the illustration I have shown a plurality of lines are represented upon which a plurality of subscribers stations are located, and for convenience of illustration I have shown two stations B C on one series of lines and but one station D on other lines. A plurality of lines or conductors l 2 3 4 5 6 are arranged in pairs, and there may be any convenient number of such pairs of lines in each series of lines. At the central office each pair of lines is provided with a spring-jack, as ct l) c, the circuits of said pairs oflines being normally closed at said jacks, but adapted to be broken thereat. In the circuit of each pairA of said lines at central I provide normally closed keys d efor the like, adapted to break the circuit of the corresponding pair of lines. The details of the jacks and keys and the circuits therefor that I have shown are as follows: Conductor 1 connects with a contact 7, that is in normal engagement with a contact 8, connected by a conductor 9 with a contact 10 in normal'engagement with a contact 11, connected by a conductor 12.With a contact 13, that is in normal engagement with a contact 14, connected by a conductor 15 with a battery 16, connected with ground at 17. The contact 7a of the jack is connected with conductor 2 and in normal engagement with a contact 8, connected by a conductor 9a with a contact 1l:L in normal engagement with a contact 10, from whicha conductor 12@L leads to the magnet of .a suitable drop 18, from which a conductor 12b 'leads to the side of battery 16 opposite its connection with conductor 15, and the contact 14 is operated bythe shutter of drop 18 to make and break circuit at contact 131. The key d is adapted to operate contacts 10 10n to break circuit between said contacts and the contacts 11 11a, and the contacts 7 7a of the jack are adapted to be operated by a plug (hereinafter referred to) to break circuit with the contacts 8 8a. It will be understood that a pair of line conductors are .normally closed at central and include a battery and drop in the circuit and also that a ground, as 17, is connected with said conductors, Which ground is for a purpose hereinafter explained. The keys d2, e2, and f2 are adapted to place the operators telephone-receiver E in circuit with a pair of lines connected thereto, as by con- ICO tacts 22 24 and 23 25, the keys d2, e2, and'f2 being part of keys d, e, and f, respectively, but shown separate for convenience. It will be understood that when a call is received at central at the drop 18 the operator actuates the key connected with the pair of lines associated with the operated drop, thereupon breaking the circuit of the lines at 11 and 10a 11a and closing the circuit ot' the receiver E at 22 24 and 23 25, respectively, thereby connecting said receiver with such lines.

Each pair of lines 1 2, 3 4, 5 6 is provided with a key, a drop, contacts, and conductors, as before described with relation to the pair of lines 1 2 and which need not be further detailed here other than to say that. all of the y keys serve to break the normal circuit of the corresponding pair of conductors and to connect the telephone-receiver therewith, and I have shown that the magnets of all the drops are connected with conductor 12b, and allthe contacts 13 are connected with conductor 15,

thus using a single battery for a plurality of pairs of lines, although each pair of lines could be provided with a separate battery. The pairs of lines of the system are to be connected together by plugs and a plug-cord in Well-known mannerthrough the jacksctb c.

At the various stations B C'D, duc., connected with the different lines, are-located electrically-operating devices adapted to sev lectapairof idle lines, connect the telephonereceiver with such pair, and produce a signal or call at central over the'pairof lines or conductor so selected. The devices and circuits I have provided for effecting the abovementioned operations are as follows: At each f subscribers station, as B C D, is an insulated support or base, as 30, to which are connected a plurality of contacts 31 32, arranged in pairs., the contacts 31 each being connected: with one line of a pair of lines, as l 3 5, as by spur-wires 3.3 34 35, and the contacts 32 are'each connected with a correspondingline of a pair of lines, as 2 4 6, as by spur-wires 36 37 38. Thus a pair of contacts 31 32 are connected with a pair of lines or conductors ofa plurality of lines, and so on for each pair of contacts, and the contacts 31 32 in each station on a plurality of lines are similarly connected in pairs with pairs of lines or conductors. In each instrument is a circuitcontroller 39, shown in the form of an arm, pivotally carried by the support 30, as by a shaft 40, to whicharm is rigidly connected a 4rack 4l, shown in the form of a sector and which ycontacts are adapted tov engage the contacts 31 and 32, respectively. The contacts 31 32 are shown arranged relatively to contacts 31a 32, so that as the latter are carried back and forth by the movement of arm 39 they will make electrical connection with the contacts 31 32in pairs, respectively. The arm 39 is normally held in such position that the contacts 31 32 will be out of engagement with contacts 31 32 and at one side of the series of the latter. Arm 39 is shown held in such position by means of the receiver 43 at the subscribers stations, for which purpose the hook 44 is shown pivotally carried by support 30 and provided with an extension 44a, adapted tovengage projection 42 to hold arm 39 in the position indicated in Figs. 1 and 2 when the receiver is upon the hook. Vhen the receiver is removed from hook 44, a spring connected with the latter raises it, and thereby carries extension 44a away from projection 42 to enable arm 39 to travel, and the latter may be caused to travel at a predetermined speed by suitable means, such as a gearing. The contact 31a is connected with a movable contact 50, as by means of arm 39 and a conductor 51, connecting said arm with contact 50, although arm 39 could be electrically connected with contact 50 through the mechanism. The contact 50 is in normal engagement with a contact 52, from which a conductor 53 leads to a magnet 54, that is connected with ground, as 55.

56 is a contact adapted to be engaged by contact 50 and connected by a conductor`57 with one terminal of receiver 43, the other terminal of which receiver is connected by a conductor 58 with contact 32, Thus contact31iL is normally in circuit with magnet 54 to ground 55; but when a complete circuit is established for magnet 54 its armature 54a I causes devices to operate contact 50 to break circuit at 50 52 and establish circuit at 50 56 through the receiver 43. The contact 50 is shown carried by a bar 59, that is pivotally connected with a spring-actuated arm 60, pivotally carried by support 30, as at 60, a spring 61 acting to move contact 50 from engagement with contact 52 into engagement 'with contact 56, the arm 60 being held in its normal position by armature 54a ot magnet 54, whereby contacts 50 and 52 are normally in engagement, as clearly shown in Figs. l and 4. A dog 62 (shown supported by stud or shaft 60a) is adapted to engage the rackteeth 41 when arm 60 is released by armature 54a; but said dog is normally held out of the range of said teeth, as by means of a pin 62a, carried by arm 60. (See Fig. 4.) A pin 63, carried by rack 41 and arranged to engage a projection o0b of arm 60, serves to restore said arm to its normal position when said rack has been returned to its normal position by the action of hook 44 and the receiver 43 hanging thereon. (See Fig. 4.) It will be understood that in the normal positions of the parts the rack 4l is free to travel under dog 62, but that when magnet 54 is energized IIC its armature 54L will release arm 60, whereupon spring 61 will move said arm and dog 62 will engage a tooth of rack 41, and thus check the movement of arm 39, while the same movement of arm60 causes contact 50 to break circuit at 52 of magnet 54 and establish circuit at 56 for the corresponding receiver. A

The complete operation of my improvements may be described as follows: Suppose a subscriber at a station, as B, desires to communicate with another Subscriber'. He simply removes his receiver 43 from its hook 44, whereupon the latter rises and releases rack 41 and arm 39, which immediately begin to move, as to the right in Fig. 1. If the pair of lines 1 2 are idle, as soonas contacts 3la 32a engage the pair of contacts 31 32, respectively, connected with conductors 2 and 1, circuit will be established for magnet 54 to ground at central as follows: from ground at the calling-subscribers station through 54, 53, 52, 50, 5l, 39, 3l, 31, 33, 1, to contact 7 at central, thence through 8, 9, 10, 11, 12, 13,14, 15, and battery 16 to ground 17. Armature 54a will release arm 60, whereupon the latter will be moved under the iniiuence of its spring and allow dog 62 to engage the iirst tooth of rack 41, and thus prevent further movement of arm 39, thereby holding the contacts 31EL 32a in engagement with contacts 31 and 32 of lines 1 2, and arm 60 will at the same time move contact 50 to break circuit at 52 and establish circuit at 50 56 through the receiver 43, whereupon a closed metallic circuit between the calling-subscribers sta.- tion and central, including the drop 18, connected with line 2, will be established as follows: from contact 50 at the calling-station, through 51, 39, 31a, 31, 33, 1, 7, 8, 9, 10, 11, 12, 13, 14, 15, battery 16, conductor 12b, through the magnet of drop 18, 12a, 10, l1, 9, 8, and 7a to line 2, thence along line 2 to 36 and 32 at B, thence through 32a 58, receiver 43 57 and contact 56 back to contact 50. The shutter of drop 18 will now drop and break circuit at 13 14, so that if another subscriber on the same series of lines should attempt to call central his arm 39 would not stop in connection with the contact 3l 32, connected with lines 1 2, because his magnet 54 could not find a circuit to battery and ground at central; but his arm 39 would pass on and would be arrested in connection with a pair of contacts 31 32, connected with a pair of idle conductors,through one of which a circuit could be established for his magnet 54 to battery 16 and ground 17 at central. When the operator at central replies to the signal, she first operates the key, as d, which breaks the circuit of linesl 2 at 10 11 and 10al 1l, but establishes the circuit of said lines through the receiver E at 22 24 and 23 25, respectively. Being told which subscriber is desired the operator at central calls the subscriber desired by means of any suitable calling-circuit, which Ihave not considered neces sary to illustrate. The called subscriber thereupon removes his receiver 43 from its hook 44, whereupon the devices at his station se lect a pair of idle conductors, and thus operate the corresponding drop 18 at central. The operator at central thereupon connects the jacks of the calling and the called subscribers by plugs and cord in well-known manner. The placing of a plug in the jack a at central causes the normal circuit of lines 1 2 to be broken at 7 8 and 7 a 8, respectively; but circuit for the connected lines will be established through the plug and cord by means of contacts 7 and 7a, which respectively connect with the tip and sleeve 65b of plug 65, said tip and sleeve, respectively, breaking circuit between contacts 7 8 and 7a 8a. When the subscribers have finished using the line, they merely hang receivers 43 upon hooks 44, whereupon the latter will be drawn down and through the projections 44a and 42 will restore arms 39 to their normal positions, and pins 63 of racks 41 will act on projections 60b to movearms 60 to their normal positions to be again held by armatures 54a, thereupon breaking circuits at 50 56 and restablishing the normal circuits at 50 52 for magnets 54. The operator at central removes the plugs from the jacks, and the shutters having been restored to normal at any suitable time the lines will be in condition for use again.

To provide a clearing-out signal at central, I have shown bridged across the strands of the plug-cord a magnet 66 and battery 67.

IOC

(See Fig. 1.) The battery 67 is shown located between two coils of magnet 66, the armature 68 of magnet 66 being utilized as a clearing-out indicator.' Thus while two pairs of lines are in use the current from battery 67 will ow on either pair of lines, thus engaging magnet 66, which will attract armature 68 to :indicate that the lines are in use, and when both receivers v43 are hung upon their hooks the circuit will be broken at 50 56, as before explained, and thereupon the indicator 68 will drop to indicate that the subscribers have finished with the line and the plugs can be removed from the jacks, thus restoring the lines to their normalconditions.-

I do not limit my invention to the details of improvement shown and described, as they may be varied without departing from the spirit thereof. y

Having now described my invention, what I claim is 1. In a telephone system, a central oiiice, a plurality of lines leading therefrom to' subscribers stations, means connected with said lines at central for producing a signal., and automatic electrically-operating devices at subscribers stations also connected with said lines for selecting a pair of idle lines and establishing a circuit over said lines through the signal-producing means.

2. In a telephone system, a central oiiice, a plurality of lines leading therefrom to subscribers stations pairs of which are normally IIO `connected together at one part at central and automatic electrically-operating devices associated with said lines at subscribers stations and arranged to establish a circuit fo any idle pair of lines.`

3. In a telephone system, apiurality oflines pairs of which are normally connected at one part, a signaling instrument in the circuit of each pair of lines, automatic electrically-operating devices connected with said lines and arranged to establish a circuit for any idle pair of lines to operate the signaling instrument connected therewith, and devices to be operated bysaid signalinginstrument to break the normally connected circuit of the corresponding lines.

4. In a telephone system comprising a plurality of lines arranged in pairs that are normally closed at one part, a signaling instrument connected with each pair of lines and 'arranged to break the circuit, a plurality of electrically-operating devices each associated with said lines and arranged to select a pair of idle lines and establish circuit thereover for a receiver to thereby operate the corresponding signaling instrument and break the circuit of such lines, and means for reestablishing the circuit of said lines for the connected receiver. v

5. In atelephone system, a plurality oflines arranged in pairs, signalinginstruments connected therewith, means connected with said signaling instruments to automatically break the circuit of said lines, jacks connected with said lines for restablishing the circuit thereoi", a plurality of automatic electrically-operating. devices each associated with said lines and arranged to select a pair of idle lines to establish and maintain a circuit thereover for a telephone-receiver.

6. Inatelephone system, a plurality oflines arranged in normally connected pairs, signaling instruments connected with said pairs of lines, means for breaking the circuit of said lines upon the operation of the signaling instrument, and a plurality of electrically-operating devices each associated with said lines, said devices each having a magnet to cause said devices to select a pair of idle lines and maintain connection therewith.

7. Inatelephonesystem, apluralityoflines normally connected at one part and one line of each pair also being connected to ground, means to break the connectionv between a pair of lines upon circuit being` established to ground over one line of a pair, and a plural- -ity of electrically-operating devices associated with said pairs of lines and arranged to select and establish ground circuit over a line of an idle pair to cause the circuit of such line to be broken.

8. In a telephone system, a pluralityof lines normally connected at one part and one line of each pair also being connected to ground, means to break the connection between a -pair of lines upon circuit being established to ground over one line of a pair, and a plurality of electrically-operatin g devices associated with said pairs of lines and arranged to select and establish ground circuit over a line of an idle pair to cause the circuit of such line to be broken, the magnet of such devices being included in such circuit and thereupon causing the selected pair of lines to be connected for a telephone-receiver.

9. In a telephone system, a plurality of lines normally connected in pairs, contacts connected with each pair, a drop in the circuit of each pair to cause said contacts to break the circuit, and a plurality of electrically-operatingdevices associated with said pairs of lines arranged to select and close the circuit over a pair of idle lines to operate the drop and break the circuit at said contacts.

lO. In a telephouesystem, a plurality of lines arranged in pairs, and a plurality of electrically-operatin g devices associated with said pairs of lines and each comprising a magnet, movable contacts to connect with any pair of lines, a contact 50 in the circuit ot' one movable contact and in the normal circuit of the magnet, and acontact connected with the other movable contact and in circuit with a receiver and arranged to be connected with contact 50 to close circuit between a pair of idle conductors and the receiver.

11. In a telephone system, a plurality of lines and a plurality of electrically-operating devices associated with said lines and each comprising a magnet, a contact connected therewith, a contact connected with a receiver, a movable contact to engage said contacts, means controlled by said magnet for operating the movable contact, a pair of movable contacts adapted to be connected with any pair of lines and controlled by said devices, one of said movable contacts being connected with the first-mentioned movable contact and the other contact of said pair being connected with a receiver.

12. In a circuit-controlling device, a pair of contacts, an arm carrying the same, a rack connected with said arm, a telephone-hook to hold said rack and arm in the normal position and adapted to release the same, means for moving said arm and rack when released, an arm 60, a magnet to control the same, and a dog controlled by arm 60 and normally held out of engagement with the rack and adapted to engage the same upon the operation of arm 60. v

13. Acircuit-controlling device comprising a pair of contacts, an arm carrying the same, a rack connected with said arm, a dog to control said rack, and an arm 60 to control said dog, arm 60 having means to hold the dog from normal engagement with said rack, said rack having means to restore arm 60 and the dog to their normal conditions.

14. A circuit-controlling device comprising a pair of contacts, an arm carrying the same, a rack' connected with said arm, a telephone- -hook having an extension adaptedto hold IOC IIC

and release said arm and rack, a movable l gaged by the movable contact and also conarm 60, a magnet having an armature ar nected With a receiver, said receiver being ranged to hold arm 60in the normal position, connected with one of the first mentioned a dog adapted to be controlled by arm 60 to contacts, the movable contact being connect- 5 check the movement of said rack and its arm ed With the other of the first-mentioned con- 15 upon the operation of said armature, a movtacts.

able contact connected with arm 60 to be op- CHAS. B. SMTH. erated thereby, a contact in normal oonnec- Witnesses: tion With the movable contact and also con- T. F. BOURNE,

1o nected with said magnet, a contact to be en- F. E. TURNER. 

